You can fill them individually and they operate for up to 24 hours straight with no problem. Click continue reading for the entire Vicks V790 GermFree Humidifier review.

Vicks FilterFree Cool Mist Humidifier requires no filter and offers hassle-free maintenance and operation. The humidifier features a 1.2-gallon tank, which can run for up to 30 hours between fillings.